Hi all! I’ve been working through some basic lessons in electronics. I’m working on the capacitor section that deals with using capacitors and resistors as a filter. So I set a simple test circuit. I’ve setup my computer to create a sine wave via the sounds card. I then connect a wire from the sound card to my test board. On the test board I have a .22uf capacitor and a 1.5 ohm resistor (+/- 20%). The configuration is attached. Then I connect to my scope. I have tried to setup the capacitor and resistor as both a high and low pass filter. However, what I’m seeing is that in low pass, I’m blocking all (at least all that my 20Mhz scope can see) AC, and in High Pass I’m passing all AC.
My understanding is that with a 1.5Ohm resistor and a .22uf cap I should be dealing with ~3khz. Meaning the low pass should pass anything below that, and the high pass should pass anything above that. However, that isn’t what I see… Is my math wrong? Where am I going wrong?
Below is a basic drawing of my low pass configuration. Thanks for any tips and help!